Blades for compressors and turbines



Feb. 23, 1960 E. A. STALKER 6 BLADES FOR COMPRESSORS AND TURBINES FiledFeb. 23, 1955 IN V EN TOR.

Fr g- 5 ML United States Patent BLADES FOR COMPRESSORS TURBINES EdwardA. Stalker, Bay City, Mich, assignor to The Stalker Corporation, acorporationof Michigan- Applicati'on February 23, 1955, SeriallNo.489,945

3 Claims. (Cl. 253-77) This invention relates to hollow blades,particularly sheet metal blades, for compressors and turbines.

An object of the invention is to provide a structure for the bladeswhich is light and strong.

Another object is to provide a sheet metal blade having light and stronginternal structure for supporting the blade walls.

Other objects will appear from the description, drawings and claims.

The above objects are accomplished by the means illustrated in theaccompanying drawings in which- Fig. 1 is a side elevation of a bladeaccording to this invention;

Fig. 2 is a section on line 22 in Fig. 1;

Fig. 3 is a fragmentary enlarged view of the convex side of the blade ofFig. 1;

Fig. 4 is a fragmentary section on line 4-4 in Fig. 3;

Fig. 5 is a fragmentary section on line 5-5 in Fig. 3;

Fig. 6 is a section on line 6-6 in Fig. 3; and

Fig. 7 is a fragmentary section on line 7-7 in Fig. 2.

Compressor or turbine blades to be light in weight employ thin wallsenclosing hollow interiors. The walls tend to vibrate locally often tothe extent that they develop fatigue cracks and disintegrate. Thisinvention provides means of supporting the walls at relatively closeintervals to exclude these local vibrations. The supporting means alsogreatly increases the strength of the blade to bending and twistingactions.

Referring now to the drawings, the blade is indicated generally as 10,Figs. 1 and 2, comprising the upper or convex wall 12, the lower orpartially concave wall 14, base 16 and internal structural means 18.

The upper and lower walls are juxtaposed in spaced relation defining thehollow interior 20. They are supported one on the other at the leadingand trailing edges 22 and 24 respectively and fixed together at theseedges.

The blade walls and the internal structural means 18 are fixed in anopening 30 in the base 16.

The internal structural means comprises one or more beaded or indentedbeams extending along a major extent of the blade span which is thedimension extending outward from the base 16. For instance in Figs. 1,2, 3 and 6 the front and rear beams 40 and 42 respectively extendpreferably along the whole span. The front beam has the upper flangemeans '44 and the lower flange means 46 each integral with the verticalfront and rear webs 5'4 and 48, and faying the inner surfaces of upperand lower walls 12 and 14, respectively.

Each upper flange means has the beads 50 (Fig. 3) each with its majordimension of length preferably directed at a substantial angle to thechord direction which is perpendicular to the direction of the span.Preferably some heads 52 have their major direction at a substantialangle to the beads 50 or parallel to the chord direction.

The front vertical portion of the beam at the junction of the upper andlower flange means constitutes a vertical front web 54. The diagonalbeads 50 form with this front web 54 and rear web 48 a truss or systemwhich 2,925,996 Patented Feb. 23, 1960 2'. can sustain loads normal: tothe span and parallel to the chord direction. A V-shap'e'd stiffener orshock absorbing element 55" is located in the hollow nose portion of theblade forwardly of web 54 and is bonded to the upper and lower bladewalls" by fused metal. Thus the structure is very strong in bending andtorsion.

Each diagonal bead 50 is indented inwardly. That is it extends in depthinwardly of theblade interior preferably into contact with the lowerflange means as shown in Figs. 2, 5 and 6 and isflkedther'etb by fusedmetal.

The beads- 52, Fig. 4, preferably extend in depthinwardly for only' ashort distance and do not reach the lower flange means.

The beads 50 and 52 divide the surface areas of the blade walls intosmall increments of area such as 60 in Fig. 3. These are suflicientlysmall that they will not undergo significant vibration when the blade isbeing rotated in use.

The rear beam means 42 is similar to the front one. It includes avertical front web 71, the upper flange means 72 and the lower flangemeans 74 lapped and joined at 76, preferaby by fused metal. The upperflange means has the diagonal beads and the chordwise beads 82. Thediagonal beads 80 extend in depth inward similarly to beads 50 as shownparticularly in Fig. 5.

The flange means fay the inner surfaces of the adjacent walls of theblade, either upper or lower wall, and are fixed to the respectiveadjacent wall by fused metal, preferably by high temperature solder.

It will now be clear that I have disclosed a light structure for ablade, one which provides great strength against bending and twistingand which supports the outer walls of the blades at close intervalsexcluding significant local vibrations.

While I have illustrated specific forms of the invention, it is to beunderstood that variations may be made therein and that I intend toclaim my invention broadly as indicated by the appended claims.

I claim:

1. In combination in a fluid turning blade for compressors and turbines,an upper wall and a lower wall juxtaposed and spaced apart alongportions thereof defining a hollow interior of said blade, and beammeans within said interior comprising fro'nt and rear webs extendingalong a major portion of the spanwise length of said blade, wallsdefining upper and lower flange means extending chordwise from one saidweb to the other and spanwise along a major portion of the spanwiselengths of said webs, said upper flange means faying the inner surfaceof said upper wall, said lower flange means faying the inner surface ofsaid lower wall, at least one of said flange means having a plurality ofbeads indented inwardly therein, each said bead having its major lengthdirected at a substantial angle with respect to the chord direction ofsaid blade, and fused metal means between each said flange means and theinner wall surface adjacent thereto fixing due to the other.

2. In combination in a fluid turning blade for compressors and turbines,an upper wall and a lower wall juxtaposed and spaced apart alongportions thereof defining a hollow interior of said blade, and beammeans within said interior comprising fro'nt and rear webs extendingalong a major portion of the spanwise length of said blade, wallsdefining upper and lower flange means extending chordwise from one saidWeb to the other'and spanwise along a major portion of the spanwiselengths of said webs, said upper flange means faying the inner surfaceof said upper wall, said lower flange means faying the inner surface ofsaid lower wall, at least one of said flange means having a plurality ofbeads indented inwardly therein, each said bead having its major length3 a directed at a substantial angle with respect to the chord directionof said blade, each said bead extending inward into contact with theopposite wall of said blade and being fixed thereto, and fused metalmeans fixing each said flange means to its adjacent wall.

3. The combination as defined in claim 1 in which each said bead has itslength extending from a locality adjacent said front web to a localityadjacent said rear web at a substantial angle with respect tothe'spanwis'e direction. i 1

References Cited in the file of this patent UNITED STATES PATENTS2,230,393 Thomson 'Feb. 4, 1941 Pecker Nov. 7, 1944 La Motte Oct. 12,1948 Bragdon Mar. 22, 1949 FOREIGN PATENTS Great Britain 1913 GreatBritain May 28, 1948 Great Britain Feb. 9, 1955 Germany Feb. 22, 1954Germany Oct. 20, 1952 Germany Dec. 22, 1952 Germany Apr. 27, 1953Germany Oct. 8. 1953

